Tracheobronchial Y-Stents, Delivery Catheters And Delivery Apparatus, And Methods For Delivering Bronchial Y-Stents

ABSTRACT

Y-stents and delivery apparatus for delivering the Y-stents include a delivery catheter with an open distal end having two, circumferentially opposed extensions separated by two receiving portions which receive an anatomical junction.

RELATED APPLICATION DATA

This application claims the benefit of Provisional Patent ApplicationSer. No. 62/167,882 filed on May 28, 2015, which is hereby incorporatedby reference.

Disclosed are Y-stents, delivery catheters and delivery apparatus forY-stents, and methods for delivering Y-stents. Disclosed deliverysystems are particularly suited for use in the placement of stents atjunctions within bronchi, such as at the junction of the right principalbronchus (RPB) and left principal bronchus (LPB), and at the junction ofthe left caudal lobe bronchus (LB2) and the left cranial lobe bronchus(LB1).

BACKGROUND

Various ailments and trauma can lead to the collapse of bronchialairways in humans and other mammals. For example, neoplastic occlusion,or chronic mitral valve disease in dogs often leads to the collapse ofthe left main bronchial stein.

SUMMARY

Catheters and other devices for delivering Y-stents, such as Y-shapedbronchial stents are disclosed. The bronchial Y-stents are preferablyformed of braided or woven nitinol, but other collapsible, biocompatiblematerials including alloys and polymers are also suitable stentmaterials. As used in the medical field, the term “Y-stent” indicates astent having a trunk and two branches. The delivered Y-stent ispreferably collapsible into a smaller configuration so that it can becompressed into a delivery catheter and placed within a patient via atranscatheter procedure, and has sufficient inherent shape memory sothat when pushed from the delivery catheter the Y-stent takes itsoriginal desired shape. The Y-stent is positionable at the junction oftwo airways and extends from one airway into two branching airways torestore/maintain patency in the airways around that junction. Thepreferred woven nitinol material provides desired flexibility and allowstissue ingrowth and normal mucociliary clearance. Unlike some, lesscompressible materials, the nitinol is less likely to cause erosion ofthe airway and long term problems with mucociliary clearance.

The disclosed delivery apparatus for delivering the Y-stents comprises adelivery catheter with an open distal end having two, circumferentiallyopposed extensions separated by two receiving portions configured to bepositioned over the desired bronchial junction which defines the branchin the airway during placement of the Y-stent. During a placementprocedure, the extensions of the delivery catheter are positioned toextend distally of the bronchial junction when the receiving portions atthe distal end portion of the delivery catheter receive the bronchialjunction.

The “open” or “unobstructed” distal end of the delivery catheter iscompletely unobstructed by any structure of the delivery system ordelivery kit so that the only forces which need to be overcome whendeploying the stent from the delivery catheter are the frictional forcesbetween the collapsed Y-stent and the inner walls of the deliverycatheter. In other words, the distal end of the delivery catheter iscompletely unobstructed to minimize or eliminate proximally directedforces on the stent during the withdrawal of the delivery catheter andafter the stent has been properly positioned.

Preferred delivery catheters comprise at least one flexible elbow tofacilitate placement around bends in the tracheobronchial airways. Apreferred delivery system comprises a delivery catheter, a Y-stent, ahollow plunger shaft, and two guide wires. The guide wires both extendthrough the delivery catheter, the hollow plunger shaft and the trunk ofthe Y-stent. One guide wire extends through a first branch of theY-stent while the other guide wire extends through the other branch ofthe Y-stent. During placement of the Y-stent into a patient, the surgeonextends the guide wires into the two target airways, i.e. with eachguide wire going into one airway, to help guide the distal extensions ofthe delivery catheter and each of the branched legs of the Y-stent intotheir respective desired positions. The flexible elbow(s) of thedelivery catheter facilitate placement of the catheter around anyproximal curves and bends, and into the desired airway proximate thejunction of the target airways. As used herein, the term “targetairways” refers to the branches of the tracheobronchial passages whichreceive the branches of the Y-stent.

Methods comprise the step of disposing a Y-stent in a delivery catheter,positioning the delivery catheter in an airway proximate a junction anddisplacing the Y-stent from the delivery catheter at least partiallyinto two airways. One method comprises positioning the receivingportions of the distal end of the delivery catheter over the junction ofthe airway, e.g. over a portion of the carina, advancing a plunger shaftwithin the delivery catheter while maintaining the stent in position,then withdrawing the delivery catheter in a manner which permits thebranches of the stent to at least partially expand before the trunk ofthe stent is out of the delivery catheter. The expansion of the branchesof the stent before the stent is entirely out of the delivery catheterreduces the tendency for the stent to spring proximally and dislodgefrom its optimum placement on the bronchial junction. Thus there arethree aspects of the disclosed embodiments which facilitate properplacement and minimize the risk of unintended, proximally-directeddislodgement of the Y-stent after it has been positioned over ananatomical junction: the unobstructed distal opening of the deliverycatheter, the outwardly directed expansion forces of the stent itselfacting on the airways and the plunger shaft.

Another step comprises positioning, preferably pre-positioning, twoguide wires through the same lumen of the delivery catheter, through thelumen of the plunger shaft, through the trunk of the Y-stent and oneeach through the branches of the Y-stent. During surgery, the guidewires are extended distally into the target airways prior to thedisplacement of the Y-stent from the delivery catheter in order to guidethe branches of the Y-stent into the proper airways.

Another method comprises positioning a collapsed stent and two guidewires into a delivery catheter having distal receiving portions,positioning the delivery catheter into a patient, advancing the guidewires, positioning the receiving portions of the distal end of thedelivery catheter over the junction of an airway, e.g. over a portion ofthe carina, advancing a plunger sheath within the delivery catheter tourge the stent at least partially out the distal end of the cathetersuch that each branch of the stent enters a separate anatomical branchat the target anatomical junction and such that each branch of the stentexpands to some extent, then withdrawing the delivery catheter in theproximal direction. During the withdrawing step, the branches of thestent are left in the respective target airways.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a Y-stent.

FIG. 2 is a bottom perspective view of the Y-stent of FIG. 1.

FIG. 3 is a front view of a second Y-stent.

FIG. 4 is front view of a third Y-stent.

FIG. 5 is a distal, perspective view of a delivery catheter.

FIG. 6 is a distal, perspective view of the delivery catheter of FIG. 5.

FIGS. 7 and 7A are a partial side view and a partial distal, perspectiveview of a delivery catheter of an alternative embodiment.

FIG. 8 is a partial front view of the catheter of FIG. 5, with portionsof two guide wires and a collapsed stent shown in phantom.

FIG. 9 is a partial, cross-sectional view of a delivery catheter,collapsed stent, plunger shaft, and two guide wires.

FIG. 10 is a partial, top perspective view of a delivery cathetercarrying a stent (shown in phantom) through a section of a trachea.

FIG. 11 is an illustration of a delivery catheter with two guide wiresand a collapsed Y-stent positioned within a patient's lungs prior tofinal positioning of the catheter.

FIG. 12 is an illustration of a delivery catheter, guide wires andY-stent of FIG. 10 within a patient's lung positioned for placement of aY-stent.

FIG. 13 is an illustration of the delivery catheter, stent and guidewires of FIG. 10 within a patient's lungs after the stent has started toemerge from the distal end of the delivery catheter.

FIG. 14 illustrates the delivery catheter, stent and guide wires of FIG.10 within a patient's lungs with the Y-stent deployed further distallythan in FIG. 13 and with the catheter partially withdrawn.

FIG. 15 is an illustration of the delivery catheter, plunger shaft andguide wires of FIG. 10 being withdrawn after placement of the Y-stent.

FIG. 16 is an illustration of the delivery catheter, plunger shaft andguide wires of FIG. 10 further withdrawn after placement of the Y-stent.

FIGS. 17A and 17B are partial, perspective and side views of a deliverycatheter, Y-stent and two guide wires of a third embodiment.

FIG. 18 is a partial bottom, perspective view of the delivery catheter,Y-stent and two guide wires of the embodiment of FIG. 15.

FIG. 19 is a partial, bottom perspective view of a delivery catheter andY-stent of a fourth embodiment.

FIG. 20 is a partial, cross-sectional view of a delivery catheter withinternal steering cables.

FIG. 21 is a partial, cross-sectional view of a delivery catheter withexternal steering cables.

FIG. 22 is a partial cross-sectional view of a delivery catheter,collapsed stent, plunger shaft and guide wires of an another embodiment.

FIG. 23A and FIG. 23B are partial side and top views, respectively, ofthe proximal end of a delivery catheter illustrating a fixation devicefor releasably securing the plunger shaft and guide wires.

DETAILED DESCRIPTION

One preferred use of the methods, apparatus and devices disclosed is toreestablish patency in a patient's airways. One aspect of the presentinvention comprises a delivery device for a self-expanding stent, formedin the shape of a Y of woven nitinol wire. The Y-stent is particularlysuited for placement within a collapsed or partially collapsed airwayvia a transcatheter procedure. One stent is particularly suited forplacement at a bronchial junction, such as the carina tracheae. Thestent is collapsible into a compact configuration and loaded into adelivery catheter along with two guide wires. The separate branches ofthe Y-stent are positioned distally of the airway junction, with thetrunk of the Y-stent positioned proximally of the airway junction. Oneguide wire is prepositioned through the trunk and one of the branches ofthe Y-stent while the other guide wire is prepositioned through thetrunk and into the other branch of the Y-stent. The proximal ends of theguide wires extend through and out the proximal ends of the deliverycatheter and plunger shaft. During the transcatheter procedure andpreferably after the distal end of the delivery catheter is near thedesired position, each guide wire is moved distally beyond the distalend of each branch of the Y-stent, beyond the distal end of the deliverycatheter and into the respective target airways. The surgeon can confirmthe proper positioning of the guide wires and the delivery system duringthe procedure via a bronchoscope.

The Y-stent is preferably positioned within two airways via atranscatheter procedure using a delivery catheter having a distal endcomprising two circumferentially opposed extensions separated by tworeceiving portions designed to be positioned over the desired bronchialjunction. The delivery catheter also, optionally, has at least oneflexible elbow. After proper positioning of the delivery catheter overthe anatomical junction, the stent is deployed into the target bronchialpassages of a patient with the aid of a bronchoscope, plunger shaft andtwo flexible guide wires. With the guide wires positioned in therespective airways, the branches of the Y-stent are urged from thedelivery catheter into the two target airways by advancing the plungershaft within the delivery catheter. The collapsed stent will expand asspace provides, i.e. within the distal end of the delivery catheter iflarger than the tubular portion of the delivery catheter and afterexiting the distal end of the delivery catheter. After the plunger shafthas seated the Y-stent on the bronchial junction, the delivery catheteris withdrawn while the plunger shaft is held in place. During thisplacement, the stent expands into its original configuration as thedelivery catheter is withdrawn to a predetermined position over theplunger shaft.

FIG. 1 illustrates a collapsible Y-stent 20 comprising a trunk 22, rightbranch 24 and left branch 26. This Y-stent is preferably hollow and isdesigned to restore and/or maintain the patency of one or more airwayswhich have wholly or partially collapsed or which are in danger ofcollapse. In this embodiment, left branch 26 has a greater diameter andis longer than right branch 24 in order to provide a better fit betweenthe Y-stent and the target bronchial branches. This Y-stent iscollapsible for ease of delivery to the desired bronchial junction.Y-stent is preferably formed of nitinol wire which has goodbiocompatibility and shape memory after being collapsed, but can beformed of other materials such as other alloys or polymers.

FIG. 2 is a rear, distal perspective view of the stent of FIG. 1.

FIG. 3 shows an alternative braided, wire Y-stent 122 comprising a trunk121, right branch 124 and left branch 126. FIG. 3 also indicates adistance TL which is the distance from the proximal end of a stent tothe junction between the stent branches. The significance of TL isexplained below. According to this embodiment, the right branch 124 andleft branch 126 are the same length and diameter.

FIG. 4 illustrates a third Y-stent wherein the branches 224 and 226 arethe same configuration (size and shape) as each other, but slightlylonger than those of the embodiment of FIG. 3. Thus, the branches of agiven Y-stent can be the same or different lengths and/or diameters, andare preferably sized and configured to closely conform to the intendedtarget airways and bronchial junction.

FIGS. 5 and 6 are partial distal, perspective views of the distalportion of a delivery catheter 12 comprising a generally elongatedtubular portion 15 having a generally longitudinal axis. The deliverycatheter can be flexed as needed to position the distal end within apatient's bronchial airways. The distal portion of tubular portioncomprises two, spaced and circumferentially opposing extensions 14, 16comprising distal ends separated by two receiving sections comprisingproximal portions 19 which do not extend distally as far as the distalends of the extensions 14,16. The extensions are configured to extendinto the adjoining target bronchial branches when the proximal portionsof the relieved portions are placed into abutment or closely proximate abronchial junction. The distal portion of delivery catheter 12 can beconsidered as having two notches which allow the distal extensions ofthe delivery catheter to extend beyond the junction of the targetbronchial branches. In the embodiment shown in FIGS. 5 and 6, the outersidewalls of the extensions 18 are aligned with the sidewalls 17 of themore proximally located tubular portion. As shown better in FIG. 6, theinside of the delivery catheter is unobstructed.

FIGS. 7 and 7A are views of an alternative delivery catheter 112 fromperspectives similar to those of FIGS. 5 and 6. Delivery catheter 112 issimilar to delivery catheter 12, but the extensions 114 and 116 areflared outwardly such that the outer sidewalls 118 of extensions 114,116 are disposed at an angle to the sidewalls 117 of the more proximallylocated tubular portion 115. The acute angle A between an imaginaryextension of the outer sidewalls of these extensions and an imaginary,central longitudinal axis passing through the tubular portion (assumingthe tubular portion is in a straight configuration) is preferably about30° −45°. As shown better in FIG. 7A, the inside of the deliverycatheter is unobstructed.

FIG. 8 is a partial, distal view of the delivery catheter 12 of FIG. 5with a collapsed Y-stent 22 (shown in phantom) positioned within thedelivery catheter. Two guide wires 34 and 36 are also positioned so thatthey are passing through the respective branches of the Y-stent 22 andthe delivery catheter 12. While the guide wires are shown extendedbeyond the distal end of the delivery catheter in this Figure, thedistal ends of guide wires are preferably maintained within the deliverycatheter until the delivery catheter has been inserted into a patient.

FIG. 9 is a partial, cross-sectional view showing the arrangement of acollapsed Y-stent 22 positioned within a delivery catheter 12 with guidewires 34 and 36 extending through the Y-stent and a plunger shaft 40positioned proximate the proximal end of the Y-stent so that it is readypush the Y-stent out the distal end (not shown) of the delivery catheter12. As indicated earlier, the branches of the Y-stent may have differentconfigurations (sizes and/or shapes) in order to better fit withindifferent bronchial tubes. Therefore, it is necessary for a surgeon tobe able to discriminate between the two branches of the Y-stent. Inorder to facilitate the proper placement of the Y-stent, in thisembodiment the guide wires are colored differently. For example, guidewire 34 is red while guide wire 36 is green. The different colors arecoordinated with different branches of the Y-stent and can be observedby the surgeon via a bronchoscope prior to the placement of the deliverycatheter over the anatomical junction to make sure the Y-stent isproperly positioned.

FIG. 10 illustrates exemplary relative sizes of a delivery catheter 12containing a collapsed Y-stent 22 and a trachea T. While deliverycatheters of different diameters can by utilized, it is surgically moreconvenient and poses less risk to the patient if a delivery catheterhaving a diameter significantly smaller than the diameter of thepatient's trachea is used. The use of a collapsible Y-stent allows forthese advantages.

FIG. 17A illustrates the distal end of another delivery catheter 312comprising a main lumen 315, a flexible elbow portion 314 and a distalend 316. The flexible elbow portion 314 in this illustrated embodimentcomprises corrugations in the sidewall of the catheter which facilitatesthe flexing of the delivery catheter around bends in the airways. Asdescribed below and illustrated in FIGS. 20 and 21, suitable steeringstructure may be provided. According to this illustrated embodiment,distal end 316 embodiment is flared outwardly. This design provides moreroom to allow the branches of the Y-stent to begin to expand back intotheir fully expanded configuration prior to the trunk of the Y-stentexiting the delivery catheter 10. The distal portion of deliverycatheter 310 is also provided with circumferentially-spaced extensions314, 316 separated by receiving sections or cutouts 318. The distal endportion of delivery catheter 310 is configured to pass over the junctionof the target airways. Like the other embodiments shown, the distal endof the illustrated delivery catheter is also entirely open, i.e.unobstructed, to allow the unobstructed delivery of the stent onto abronchial junction. This open distal configuration minimizes anyproximally directed forces which may be exerted on the stent by theproximal movement of the delivery catheter during placement of theY-stent. The receiving portions allow branches of the Y-stent to bepositioned in the target bronchial branches and beyond the bronchialjunction prior to placement of the Y-stent and withdrawal of thedelivery catheter. The catheter may have other features and structurewhich are not illustrated in the figures. FIG. 17B illustrates anothermanner of distinguishing the guide wires. In this embodiment, guide wire336 has longitudinal stripes while guide wire 334 has circumferentialstripes. These stripes can be imprinted or molded into the guide wiresand are discernible by a surgeon during surgery via a bronchoscope.

FIG. 17A also illustrates Y-stent 320 comprising a trunk section 322, aright branch 324 and a left branch 326. The crosshatching indicates thewoven or braided wires of the exemplary stent. Additionally, a rightguide wire 334 and a left guide wire 336 extend through main lumen 312,a flexible elbow portion 314 and trunk section 322 of Y-stent 320. Rightguide wire 334 extends through right branch 324 of Y-stent 320 and leftguide wire 336 extends through left branch 326 of Y-stent 320. Guidewires can be formed of the same material(s) as known hydrophilic orhydrophobic guide wires.

FIG. 18 generally illustrates the delivery catheter 310, Y-stent 320 andguide wires 334, 336 of FIG. 17A with the Y-stent 320 in a collapsedposition within the delivery catheter 310.

FIG. 19 illustrates an alternative delivery catheter 410 comprising amain lumen 412, a flexible portion 414 and an open distal end 416. Theflexible portion 414 in this illustrated embodiment is formed of aresilient material, e.g. a rubber-like compound or polymer with similarflexibility and biocompatibility, which permits the catheter to flexaround bends in the airways. As described above in reference to theembodiment shown in FIG. 17A, suitable steering structure may beprovided. FIG. 19 also illustrates a Y-stent 420 with a wider spacebetween the stent branches. Distal end 416 of delivery catheter 410 hasa receiving section or slot 418 configured to seat on a bronchialjunction while distal extension portions of the delivery catheter extendbeyond the bronchial junction.

FIGS. 20 and 21 indicate steering mechanisms useful with the deliverycatheters. In FIG. 20, cables 55 are fixedly connected to anchors 54embedded in the distal portions of sidewalls of the delivery catheter.Cables 55 extend through steering lumens 52 to the proximal end of thedelivery catheter and terminate proximally in a steering ring 58. Bymanipulating the steering ring 58, a surgeon can cause the distal end ofthe catheter to bend in a desired direction. FIG. 21 shows a similarsteering configuration, but with the cables 155 running along theexternal sidewall of the delivery catheter.

FIGS. 22, 23A and 23B illustrate other optional features of thecomponents. FIG. 22 shows a handle structure 60 having a positionindicator knob 62 for indicating the orientation of the deliverycatheter, i.e. distinguishing between the different sides of thedelivery catheter, to the surgeon. Handle structure 60 is also at alocation TDL or tubular delivery length (TDL) which is equal to thedistance from the proximal portion of one of said receiving sections tothis indicated location. While this embodiment indicates the locationTDL with structure, i.e. the handle structure, the location TDL can alsobe “marked” or indicated with some other visible indicia such as a lineor other marking. FIG. 22 also indicates position DL on the plungershaft 40. DL is the delivery length, i.e. the distance the plunger shaftshould be inserted into the catheter to fully seat the Y-stent on theanatomical junction. Distance DL is equal to distance TDL minus distanceTL and gives the surgeon a convenient reference for seeing how theplunger shaft should be advanced relative to the delivery catheter.

FIGS. 23A and 23B illustrate a fixation device 90 in the form of a camwheel which is used to releasably secure the positions of the plungershaft and/or guide wires relative to the delivery catheter prior to thedesired deployment of the guide wires and stent during surgery. Fixationdevice 90 comprises a frame 91 with an inclined slot 94 which guides alocking wheel 92 between an advanced position which engages and squeezesplunger shaft 40 and guide wires 34,36, and a withdrawn position whichdoes not interfere with the relative movement of the plunger and guidewires relative to the delivery catheter. Frame 91 is connected todelivery catheter 12. Fixation device 90 reduces the risk of the stentbeing prematurely deployed or the guide wires slipping out of thedelivery catheter prior to surgery.

Methods comprise the step of providing a collapsible, preferably porousY-stent, preferably formed of nitinol wire, collapsing the Y-stent,disposing the Y-stent in a delivery catheter, positioning the deliverycatheter in an airway proximate a junction and displacing the Y-stentfrom the delivery catheter at least partially into two airways. Anotherstep comprises positioning the distal end of the delivery catheter overthe junction of the airway, e.g. over a portion of the carina, with thereceiving portions seated on the anatomical junction and the outerportions of the distal end and the branches of the stent positioneddistally of the bronchial junction. Another step comprises positioningtwo guide wires down the same lumen of the delivery catheter, into thetrunk of the Y-stent and one each of the guide wires into the legs ofthe Y-stent. One method comprises the step of extending the guide wiresdistally into the target airways prior to the displacement of theY-stent from the delivery catheter in order to guide the branches of theY-stent into the proper airway. One method comprises the step ofpositioning a Y-stent at least partially into two airways. One methodcomprises the step of positioning a Y-stent at the junction of twoairways. One method comprises advancing the plunger shaft within thedelivery catheter to advance the stent into the distal end of thedelivery catheter. A preferred method comprises the step of positioninga Y-stent over the junction separating two airways so that one branch ofthe Y-stent extends at least partially into one airway and the otherbranch of the Y-stent extends at least partially into the other airway.As the delivery catheter is withdrawn proximally, the branches of theY-stent are free to expand before the trunk of the stent expands.

FIGS. 11-16 illustrate the delivery catheter, stent, plunger shaft andguide wires of FIG. 17A at different times during a surgical procedure.FIG. 11 shows the delivery catheter positioned proximate an airwayjunction prior to placement of a Y-stent. The Y-stent is shown inphantom. The guide wires 134, 136 have been extended out of the distalend of the delivery catheter into two target branch airways.

FIG. 12 illustrates the delivery catheter in a more distal position withthe receiving portions on the bronchial junction and the extensions ofthe catheter positioned in the respective branch airways. The stent hasbeen advanced in the delivery catheter and has started to expand toconform to the inner walls of the distal end of the delivery catheter.

FIG. 13 shows the stent partially beyond the distal end of the deliverycatheter. As indicated, the stent expands toward its normal,uncompressed configuration when the restrictive forces of the deliverycatheter are removed.

FIG. 14 shows the delivery catheter partially withdrawn while the stentis maintained in place by the plunger shaft and the frictional forcesbetween the partially expanded Y-stent and the bronchial walls. As notedabove, the unobstructed internal distal end of the delivery catheterdoes not apply any unwanted proximally-directed forces on the stentduring this deployment.

FIG. 15 illustrates the delivery catheter withdrawn from the Y-stent andthe Y-stent properly positioned over the junction of the target airways.Specifically, Y-stent 120 is positioned with one branch of the Y-stentin each of the target airways and the trunk section in the feedingairway.

FIG. 16 shows the delivery catheter further withdrawn and the guidewires fully withdrawn from the properly placed Y-stent.

Different size delivery catheters with different sized and shapedrelieved portions can be used for different patients. The disclosedstents, delivery apparatus and methods are intended for use in humansand other mammals, such as dogs.

The open configuration of the distal end of the disclosed deliverycatheters minimizes any proximally directed forces on the properlypositioned stent by the withdrawing catheter. Additionally, since thebranches of the stent can expand while the trunk of the stent is stillpositioned in the catheter as the stent is being forced out of thedelivery catheter, the stent will be less likely to spring proximallyand become dislodged from the desired position where the crotch of thestent abuts the bronchial junction.

1. A delivery catheter for a bronchial Y-stent configured to maintainpatency between a trunk airway and two bronchial branches separated by abronchial junction, said delivery catheter comprising: a tubular portioncomprising, a proximal portion and a distal portion; said distal portioncomprising two, spaced and circumferentially opposing extensionsdefining an unobstructed distal opening; said extensions comprisingdistal ends; said extensions are separated by two, proximally extendingreceiving sections configured to receive a bronchial junction when saidextensions extend into adjacent bronchial branches, said receivingsections comprising proximal portions which do not extend distally asfar as the distal ends of said extensions, and wherein said extensionsare configured to extend into adjoining bronchial branches when saidproximal portions of said relieved portions are abutting a bronchialjunction.
 2. A delivery catheter according to claim 1 wherein saiddistal ends of said extensions extend at least 1 cm beyond said proximalportions of said receiving sections.
 3. A delivery catheter according toclaim 1 wherein said distal ends of said extensions extend at least 1.5cm beyond said proximal portions of said receiving sections.
 4. Adelivery catheter according to claim 1 wherein said tubular portioncomprises sidewalls, said extensions comprise sidewalls and saidsidewalls of said extensions are contiguous and aligned with saidsidewalls of said tubular portion.
 5. A delivery catheter according toclaim 1 wherein said tubular portion comprises a substantiallylongitudinal axis and sidewalls, said extensions comprise sidewalls andsaid sidewalls of said extensions are angled outwardly said sidewalls ofsaid tubular portion.
 6. A delivery catheter according to claim 5wherein said extensions form an acute angle of about 30° to about 45°with said longitudinal axis.
 7. A delivery catheter according to claim 5wherein said sidewalls of said extensions are contiguous with saidsidewalls of said tubular portion.
 8. A kit comprising: a deliverycatheter comprising a tubular portion; a collapsible Y-stent comprisinga trunk portion, a first branch and a second branch; a hollow plungershaft; and a first guide wire and a second guide wire, wherein saidfirst guide wire is positioned through said tubular portion, throughsaid hollow plunger, and through said trunk and said first branch ofsaid Y-stent, and said second guide wire is positioned through saidtubular portion, through said hollow plunger and through said trunk andsaid second branch of said Y-stent.
 9. A kit according to claim 8wherein said a tubular portion comprises a proximal portion and a distalportion; said distal portion comprising two, spaced andcircumferentially opposing extensions defining an unobstructed distalopening.
 10. A kit according to claim 9 wherein said stent has a trunklength (TL) which is the distance between the junction of said firstbranch and said second branch and the proximal end of said stent; saidextensions are separated by two, proximally extending receiving sectionsconfigured to receive a bronchial junction when said extensions extendinto adjacent bronchial branches, said receiving sections comprisingproximal portions; said tubular portion comprises a marked locationproximate the proximal end of said tubular portion, said tubular portioncomprising a tubular delivery length (TDL) equal to the distance fromthe proximal portion of one of said receiving sections to said markedlocation; and said plunger shaft comprising indicia at a position (DL)equal to (TDL minus TL) from the distal end of said plunger shaft.
 11. Akit according to claim 10 wherein said marked location is marked with astructure.
 12. A kit according to claim 10 wherein said marked locationis marked with visible indicia.
 13. A kit according to claim 8 whereinsaid first guide wire and said second guide wire have distinguishingindicia.
 14. A kit according to claim 10 wherein said first guide wireand said second guide wire are different colors.
 15. A kit according toclaim 8 wherein said distinguishing indicia are discernible anddistinguishable with a bronchoscope while in a pulmonary airway.
 16. Akit according to claim 8 wherein said first branch and said secondbranch have different lengths.
 17. A kit according to claim 8 furthercomprising a releasable fixation device for releasably securing theposition of at least one of said plunger shaft and said guide wiresrelative to said delivery catheter.
 18. A Y-stent comprising: a trunk; afirst branch and a second branch, wherein said first branch has adifferent configuration than said second branch; and wherein said stentcomprises braided Nitinol wire.
 19. A Y-stent according to claim 18wherein said first branch is longer than said second branch.
 20. AY-stent according to claim 18 wherein said first branch has a largerdiameter than said second branch.
 21. A method of installing a Y-stentin a bifurcated bronchial airway comprising the steps of: providing adelivery catheter comprising: a tubular portion comprising, a proximalportion and a distal portion; said distal portion comprising two, spacedand circumferentially opposing extensions defining an unobstructeddistal opening; said extensions comprising distal ends; said extensionsare separated by two, proximally extending receiving sections configuredto receive a bronchial junction when said extensions extend intoadjacent bronchial branches, said receiving sections comprising proximalportions which do not extend distally as far as the distal ends of saidextensions, and wherein said extensions are configured to extend intoadjoining bronchial branches when said proximal portions of saidrelieved portions are abutting a bronchial junction; providing a Y-stentin said delivery catheter; advancing said delivery catheter into apatient's airway so that at least one of said receiving sections abuts abronchial junction and said extensions extend into adjoining branchairways; and pushing said Y-stent out of said delivery catheter.
 22. Amethod according to claim 21 further comprising the steps of providing ahollow plunger and providing a first guide wire and a second guide wire,wherein said wherein said first guide wire is positioned through saidtubular portion, through said hollow plunger, and through said trunk andsaid first branch of said Y-stent, and said second guide wire ispositioned through said tubular portion, through said hollow plunger andthrough said trunk and said second branch of said Y-stent.
 23. A methodaccording to claim 22 wherein said step of providing said first guidewire and a second guide wire comprises providing a first guide wirewhich is visually distinguishable from said second guide wire.
 24. Amethod according to claim 22 further comprising the step of guiding saidguide wires into adjacent bronchial branches.
 25. A method of installinga Y-stent in a bifurcated bronchial airway comprising the steps of:providing a delivery catheter comprising: a tubular portion comprising,a proximal portion and a distal portion; said distal portion comprisingtwo, spaced and circumferentially opposing extensions defining anunobstructed distal opening; said extensions comprising distal ends;said extensions are separated by two, proximally extending receivingsections configured to receive a bronchial junction when said extensionsextend into adjacent bronchial branches, said receiving sectionscomprising proximal portions which do not extend distally as far as thedistal ends of said extensions, and wherein said extensions areconfigured to extend into adjoining bronchial branches when saidproximal portions of said relieved portions are abutting a bronchialjunction; providing a Y-stent comprising a trunk, a first branch and asecond branch, wherein said first branch has a different configurationthan said second branch, and positioning said Y-stent in said deliverycatheter; providing a first guide wire and a second guide wire, whereinsaid first guide wire is positioned through said tubular portion,through said hollow plunger, and through said trunk and said firstbranch of said Y-stent, and said second guide wire is positioned throughsaid tubular portion, through said hollow plunger and through said trunkand said second branch of said Y-stent, wherein said first guide wireand said second guide wire have distinguishing indicia; confirming theproper orientation of said delivery catheter with a bronchoscope;subsequently advancing said delivery catheter into a patient's airway sothat at least one of said receiving sections abuts a bronchial junctionand said extensions extend into adjoining branch airways; and pushingsaid Y-stent out of said delivery catheter.
 26. A method according toclaim 25 wherein said step of providing guide wires comprises providingguide wires of different colors.